1. Field of the Invention
The present invention relates to an optical coupler arrangement which is employed for replicating surface features of diverse types of optical devices. Moreover, the invention is directed to a novel method of accurately replicating surface features of optical devices; particularly through the utilization of the novel optical coupler arrangement.
The manufacture of diverse types of optical devices, such as optical couplers, waveguides and related kinds of devices, necessitates the formation of surface features which are intended to receive or mount optical fibers or the likes at a high degree of precision in their placement. The replication methods which are currently employed in producing surface features of optical devices, for instance, such as grooves for the containment of optical fibers, are subject to limitations inasmuch as during replication thereof, frequently encountered are distortions and manufacturing inaccuracies which are potentially caused by the types of manufacturing methods and materials which are presently employed in this technology. For instance, in applying various types of replication methods which are intended adapted to form surface features, such as optic fiber-receiving grooves in substrates, the desired processing precision during replication is adversely affected or even lost due to differences in the materials, thermal variations and surface flaws present in the replication components or masters.
Conventional optical connectors and couplers are equipped with fibers which are retained in a captive position within channels or grooves defined between the upper and lower halves of mating substrates. Generally, one of the substrates is provided with a surface which is traversed by parallel grooves, each such groove normally possessing a V-shaped cross-section. These grooves are ordinarily formed by either photolithography and/or chemical etching methods, resultingly necessitating the employment of sophisticated production equipment and tightly controlled chemical processes. Moreover, in implementing successive replications, the different types of materials and wear over time and use of the processing components lead to unacceptably high manufacturing tolerances, adversely affecting the efficacy of any optical device formed by means of such methods. Although the use of masters in replicating patterns or grooving substrates for the positioning of optical fibers or the like is widely known, the current technology in employing the photolithographic and chemical etching processes, through requiring complex arrangements and methods render the manufacture of accurate and widely diverse optical devices expensive and cumbersome. In contrast with the foregoing, the present invention improves upon the currently known replicating arrangements and manufacturing methods for producing optical devices by rendering them simpler and also being less expensive while providing a superior process and higher degree of accuracy in forming grooved or contoured surfaces on the substrate. In that connection, pursuant to the invention there is employed a pressing process adapted to essentially form a master part and a submaster which acts as a mold for the replication of couplers for optical devices. This particular type of arrangement and method of producing replicated couplers for optical devices is not at all disclosed nor suggested in the current state-of-the technology.
2. Discussion of the Prior Art
Kojima et al. U.S. Pat. No. 6,181,854 B1 describes an optical module which is adapted to be manufactured through the intermediary of transfer molding. The structure produced in forming the optical module is through the use of a molded resin and is limited to a particular single application and which cannot be readily employed to the replication of optical devices pursuant to the invention. This is because as Kojima et al. fails to provide for a pressing process to form optical fibers receiving grooving or features on a substrate in a precise manner.
Choquette, et al. U.S. Pat. No. 5,861,113 discloses the fabrication of embossed diffractive optics with a reusable release agent, such as a fluorinated silane and then applying coatings of an epoxy resin. The method described in this publication produces a plastic diffractive pattern through the pressing of a curable plastic against a master. The publication is only adapted to provide for diffractive optics and does not disclose any applicability to a wide range of optical devices where the replication method pursuant to the invention has found broad potential utilizations.
Foley et al. U.S. Pat. No. 5,500,914 discloses an optical interconnect unit and method of manufacture thereof adapted to produce an optical connector through molding. The replication method pursuant to the invention and the arrangement employs pressing procedure forming a so-called mold of a sub-master is not at all disclosed nor suggested in the patent, and consequently the present invention pertains to a broad concept of producing optical devices unlike that of the Foley et al. patent.
Boyd et al. U.S. Pat. No. 5,343,544 discloses the manufacture of optical couplers which contains aligned wave channels. Although some similarities with the inventive concept may be ascertained from this publication, the latter is limited to optical couplers and cannot be employed to the production of diverse types of devices. Moreover, the publication utilizes the use of a master wherein the mold loses precision due to material differences, thermal variations and surface flaws which may be evident in the substrates. To the contrary, unlike this patent, the inventive master is utilized in the manufacture of a final component, whereas the publication employs the master so as to produce a mold which can lose the strict tolerances during subsequent replication due to mold wear. Moreover, the invention employs a pressing process providing for precision scribing of the features into the surface of the substrate so as to enable accurate positioning of optical fibers or coupling components, whereas the publication employs less precise photolithography and silicon etching methods. Thus, the publication is limited to an aspect in affording a limited method of manufacture for fiber optic couplers and waveguide channels, unlike the present invention which enables the replication process to be employed for the most diverse types of optical devices.
Kakii et al. U.S. Pat. No. 5,416,868 describes optical connectors in which a resin molding portion is employed, including opposite open portions at top and bottom surfaces adapted to receive connector pins and optical components. The resin molding process is not adapted to provide the unique method of replication and arrangement as described herein wherein a wide array of diverse types of optical devices can be produced through a unique submaster.
Finally Shaw et al. U.S. Pat. No. 4,536,058 is directed to a method of manufacturing a fiber optic directional coupler of a completely different structure and aspect, and produces various optical fibers for tying various devices together. This has nothing in common with the novel replication method and arrangement for producing optical devices in a precise manner analogous to that disclosed by the present invention.